The following properties of the subcellular structures, namely sacroplasmic reticulum, sarcolemma and mitochondria, or bronchial muscle will be examined: a) isolation and characterization of the sarcoplasmic reticulum; b) isolation and characterization of sarcolemma; c) isolation and characterization of mitochondria; d) calcium uptake, calcium release and calcium-dependent ATPase of all three subcellular components. e) elucidation of the mechanism of action of the calcium- dependent ATPase through the measurement of: 1) ATP binding to the three membrane vesicles; 2) formation of a phosphorylated intermediate; 3) hydrolysis of the same phosphorylated intermediate; 4) the equilibrium constant for the reversible reaction E plus ATP yields (reversibly) EP plus ADP. f) the effect of isoproterenol, adrenaline, acetylcholine and histamine on all the above properties a) to e).